1. Field of the Invention
This invention relates to circuit breakers with auxiliary switches that signal the state of the breaker contacts and, more particularly, to arrangements for actuating the auxiliary switch.
2. Background Information
It is common for many circuit breakers to be provided with an auxiliary switch that signals the open or closed state of the circuit breaker contacts. Often, the auxiliary switch is offered as an option. For instance, the auxiliary switch can be added, if requested, by insertion in a compartment in a primary cover of the circuit breaker that is enclosed by a secondary cover. The plunger of the auxiliary switch extends through an opening in the primary cover where it is actuated by a projection molded on the crossbar that ties the moving contact arms of the multipole circuit breaker together. The crossbar necessarily must be stiff to assure coordinated movement of the contact arms of all of the poles. Thus, the projection on the crossbar which is molded of the same material is stiff and non-compliant.
With this arrangement, there exists the potential for an accumulation of tolerance stack up within the circuit breaker operating mechanism to provide too much or too little travel. This travel may not be sufficient enough to actuate the auxiliary switch, or, excessive travel may damage the auxiliary switch. In previous instances, customizing/modifying plunger lengths was necessary to accommodate this tolerance stack up.
There is, therefore, room for improvement in arrangements for actuating the auxiliary switches in circuit breakers.